run:
	@mvn clean package && java -jar ./target/demo-1.0.jar 
jdbc:
# demo-1.0.jar → 瘦 jar，不含 MySQL 驱动
# demo-1.0-jar-with-dependencies.jar → 胖 jar，已包含驱动和你代码
	@mvn clean package && java -jar ./target/demo-1.0-jar-with-dependencies.jar